Pygame.MOUSEBUTTONDOWN的问题

import pygame
from pygame.locals import *

pygame.init()

# 创建游戏窗口
window = pygame.display.set_mode((800, 600))

while True:
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == MOUSEBUTTONDOWN:
            if event.button == 1:  # 左键按下
                print("左键按下")
            elif event.button == 2:  # 中键按下
                print("中键按下")
            elif event.button == 3:  # 右键按下
                print("右键按下")